Transmission of sidelink-synchronization signal block of nr v2x

ABSTRACT

One embodiment of the present disclosure provides a method by which a first apparatus transmits a sidelink-synchronization signal block (SL-SSB). The method is characterized in comprising the steps of: determining a first resource considered that a first SL-SSB is transmittable; and transmitting the first SL-SSB to a second apparatus based on the first resource. Accordingly, apparatuses based on V2X communication in wireless communication system may efficiently relay or transmit and receive SL-SSB based on a slot format.

BACKGROUND OF THE DISCLOSURE Field of the Disclosure

This disclosure relates to a wireless communication system.

Related Art

Sidelink (SL) communication is a communication scheme in which a directlink is established between User Equipments (UEs) and the UEs exchangevoice and data directly with each other without intervention of anevolved Node B (eNB). SL communication is under consideration as asolution to the overhead of an eNB caused by rapidly increasing datatraffic.

Vehicle-to-everything (V2X) refers to a communication technology throughwhich a vehicle exchanges information with another vehicle, apedestrian, an object having an infrastructure (or infra) establishedtherein, and so on. The V2X may be divided into 4 types, such asvehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I),vehicle-to-network (V2N), and vehicle-to-pedestrian (V2P). The V2Xcommunication may be provided via a PC5 interface and/or Uu interface.

Meanwhile, as a wider range of communication devices require largercommunication capacities, the need for mobile broadband communicationthat is more enhanced than the existing Radio Access Technology (RAT) isrising. Accordingly, discussions are made on services and user equipment(UE) that are sensitive to reliability and latency. And, a nextgeneration radio access technology that is based on the enhanced mobilebroadband communication, massive Machine Type Communication (MTC),Ultra-Reliable and Low Latency Communication (URLLC), and so on, may bereferred to as a new radio access technology (RAT) or new radio (NR).Herein, the NR may also support vehicle-to-everything (V2X)communication.

FIG. 1 is a drawing for describing V2X communication based on NR,compared to V2X communication based on RAT used before NR. Theembodiment of FIG. 1 may be combined with various embodiments of thepresent disclosure.

Regarding V2X communication, a scheme of providing a safety service,based on a V2X message such as BSM (Basic Safety Message), CAM(Cooperative Awareness Message), and DENM (Decentralized EnvironmentalNotification Message) is focused in the discussion on the RAT usedbefore the NR. The V2X message may include position information, dynamicinformation, attribute information, or the like. For example, a UE maytransmit a periodic message type CAM and/or an event triggered messagetype DENM to another UE.

For example, the CAM may include dynamic state information of thevehicle such as direction and speed, static data of the vehicle such asa size, and basic vehicle information such as an exterior illuminationstate, route details, or the like. For example, the UE may broadcast theCAM, and latency of the CAM may be less than 100 ms. For example, the UEmay generate the DENM and transmit it to another UE in an unexpectedsituation such as a vehicle breakdown, accident, or the like. Forexample, all vehicles within a transmission range of the UE may receivethe CAM and/or the DENM. In this case, the DENM may have a higherpriority than the CAM.

Thereafter, regarding V2X communication, various V2X scenarios areproposed in NR. For example, the various V2X scenarios may includevehicle platooning, advanced driving, extended sensors, remote driving,or the like.

For example, based on the vehicle platooning, vehicles may move togetherby dynamically forming a group. For example, in order to perform platoonoperations based on the vehicle platooning, the vehicles belonging tothe group may receive periodic data from a leading vehicle. For example,the vehicles belonging to the group may decrease or increase an intervalbetween the vehicles by using the periodic data.

For example, based on the advanced driving, the vehicle may besemi-automated or fully automated. For example, each vehicle may adjusttrajectories or maneuvers, based on data obtained from a local sensor ofa proximity vehicle and/or a proximity logical entity. In addition, forexample, each vehicle may share driving intention with proximityvehicles.

For example, based on the extended sensors, raw data, processed data, orlive video data obtained through the local sensors may be exchangedbetween a vehicle, a logical entity, a UE of pedestrians, and/or a V2Xapplication server. Therefore, for example, the vehicle may recognize amore improved environment than an environment in which a self-sensor isused for detection.

For example, based on the remote driving, for a person who cannot driveor a remote vehicle in a dangerous environment, a remote driver or a V2Xapplication may operate or control the remote vehicle. For example, if aroute is predictable such as public transportation, cloud computingbased driving may be used for the operation or control of the remotevehicle. In addition, for example, an access for a cloud-based back-endservice platform may be considered for the remote driving.

Meanwhile, a scheme of specifying service requirements for various V2Xscenarios such as vehicle platooning, advanced driving, extendedsensors, remote driving, or the like is discussed in NR-based V2Xcommunication.

SUMMARY OF THE DISCLOSURE

A technical problem of the present disclosure is to provide a method forcommunication between apparatuses (or terminals) based on V2Xcommunication, and the apparatuses (or terminals) performing the method.

Another technical problem of the present disclosure is to provide amethod for transmitting and receiving a sidelink synchronization signalblock (Sidelink Synchronization Signal Block, hereinafter ‘SL-SSB’)between devices based on V2X communication in a wireless communicationsystem and an apparatus for performing the same.

The other technical problem of the present disclosure is to provide amethod and apparatus for relaying or transmitting an SL-SSB based on aslot format.

The other technical problem of the present disclosure is to provide amethod and apparatus for performing a sensing operation based on a slotformat and relaying an SL-SSB based on the sensing operation.

The other technical problem of the present disclosure is to provide amethod and apparatus for transmitting/receiving an SL-SSB in a situationin which a time-domain resource for a sidelink is limited. Also, theother technical problem of the present disclosure is to provide a methodand apparatus for efficiently managing transmission resources foranother sidelink channel (eg, PSCCH, PSSCH, or PSFCH) based on atransmission position of an SL-SSB.

According to an embodiment of the present disclosure, a method fortransmitting a sidelink-synchronization signal block (SL-SSB) by a firstapparatus may be provided. The method may include determining a firstresource considered capable of transmitting a first SL-SSB andtransmitting the first SL-SSB to a second apparatus based on the firstresource.

According to an embodiment of the present disclosure, a first apparatustransmitting a sidelink-synchronization signal block (SL-SSB) may beprovided. The first apparatus may include at least one memory storinginstructions, at least one transceiver and at least one processorconnecting the at least one memory and the at least one transceiver,wherein the at least one processor is configured to: determine a firstresource considered capable of transmitting a first SL-SSB, and controlthe at least one transceiver to transmit the first SL-SSB to a secondapparatus based on the first resource.

According to an embodiment of the present disclosure, an apparatuscontrolling a first terminal may be provided. The apparatus includes atleast one processor and at least one computer memory operably coupled bythe at least one processor and storing instructions, wherein, by the atleast one processor executing the instructions, the first terminal isconfigured to: determine a first resource considered capable oftransmitting a first SL-SSB, and transmit the first SL-SSB to a secondapparatus based on the first resource.

According to an embodiment of the present disclosure, a non-transitorycomputer-readable storage medium having instructions stored thereon maybe provided. Based on the instructions being executed by at least oneprocessor: a first resource that is considered to be possible totransmit a first SL-SSB is determined by the first apparatus, and by thefirst apparatus, based on the first resource, the first SL-SSB istransmitted to the second apparatus.

According to the present disclosure, a terminal (or an apparatus) mayperform SL communication effectively.

According to the present disclosure, V2X communication betweenapparatuses (or terminals) may be performed effectively.

According to the present disclosure, apparatuses based on V2Xcommunication in a wireless communication system may efficiently relayor transmit/receive an SL-SSB based on a slot format.

According to the present disclosure, apparatuses based on V2Xcommunication in a wireless communication system may perform a sensingoperation based on a slot format, and may efficiently relay ortransmit/receive an SL-SSB based on the sensing operation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a drawing for describing V2X communication based on NR,compared to V2X communication based on RAT used before NR.

FIG. 2 shows a structure of an NR system, in accordance with anembodiment of the present disclosure.

FIG. 3 shows a functional division between an NG-RAN and a 5GC, inaccordance with an embodiment of the present disclosure.

FIG. 4 shows a radio protocol architecture, in accordance with anembodiment of the present disclosure.

FIG. 5 shows a structure of a wireless frame of an NR, in accordancewith an embodiment of the present disclosure.

FIG. 6 shows a structure of a slot of an NR frame, in accordance with anembodiment of the present disclosure.

FIG. 7 shows an example of a BWP, in accordance with an embodiment ofthe present disclosure.

FIG. 8 shows a radio protocol architecture for a SL communication, inaccordance with an embodiment of the present disclosure.

FIG. 9 shows a UE performing V2X or SL communication, in accordance withan embodiment of the present disclosure.

FIG. 10 shows a procedure of performing V2X or SL communication by a UEbased on a transmission mode, in accordance with an embodiment of thepresent disclosure.

FIG. 11 shows three cast types, in accordance with an embodiment of thepresent disclosure.

FIG. 12 shows examples of the structure of an S-SSB.

FIG. 13 is a flowchart illustrating an operation of a first apparatusaccording to an embodiment of the present disclosure.

FIG. 14 shows a communication system 1, in accordance with an embodimentof the present disclosure.

FIG. 15 shows wireless devices, in accordance with an embodiment of thepresent disclosure.

FIG. 16 shows a signal process circuit for a transmission signal, inaccordance with an embodiment of the present disclosure.

FIG. 17 shows a wireless device, in accordance with an embodiment of thepresent disclosure.

FIG. 18 shows a hand-held device, in accordance with an embodiment ofthe present disclosure.

FIG. 19 shows a car or an autonomous vehicle, in accordance with anembodiment of the present disclosure.

BEST MODE FOR CARRYING OUT THE DISCLOSURE

According to an embodiment of the present disclosure, a method fortransmitting a sidelink-synchronization signal block (SL-SSB) by a firstapparatus may be provided. The method may include determining a firstresource considered capable of transmitting a first SL-SSB andtransmitting the first SL-SSB to a second apparatus based on the firstresource.

Description of Exemplary Embodiments

In the present specification, “A or B” may mean “only A”, “only B” or“both A and B.” In other words, in the present specification, “A or B”may be interpreted as “A and/or B”. For example, in the presentspecification, “A, B, or C” may mean “only A”, “only B”, “only C”, or“any combination of A, B, C”.

A slash (/) or comma used in the present specification may mean“and/or”. For example, “A/B” may mean “A and/or B”. Accordingly, “A/B”may mean “only A”, “only B”, or “both A and B”. For example, “A, B, C”may mean “A, B, or C”.

In the present specification, “at least one of A and B” may mean “onlyA”, “only B”, or “both A and B”. In addition, in the presentspecification, the expression “at least one of A or B” or “at least oneof A and/or B” may be interpreted as “at least one of A and B”.

In addition, in the present specification, “at least one of A, B, and C”may mean “only A”, “only B”, “only C”, or “any combination of A, B, andC”. In addition, “at least one of A, B, or C” or “at least one of A, B,and/or C” may mean “at least one of A, B, and C”.

In addition, a parenthesis used in the present specification may mean“for example”. Specifically, when indicated as “control information(PDCCH)”, it may mean that “PDCCH” is proposed as an example of the“control information”. In other words, the “control information” of thepresent specification is not limited to “PDCCH”, and “PDDCH” may beproposed as an example of the “control information”. In addition, whenindicated as “control information (i.e., PDCCH)”, it may also mean that“PDCCH” is proposed as an example of the “control information”.

A technical feature described individually in one figure in the presentspecification may be individually implemented, or may be simultaneouslyimplemented.

The technology described below may be used in various wirelesscommunication systems such as code division multiple access (CDMA),frequency division multiple access (FDMA), time division multiple access(TDMA), orthogonal frequency division multiple access (OFDMA), singlecarrier frequency division multiple access (SC-FDMA), and so on. TheCDMA may be implemented with a radio technology, such as universalterrestrial radio access (UTRA) or CDMA-2000. The TDMA may beimplemented with a radio technology, such as global system for mobilecommunications (GSM)/general packet ratio service (GPRS)/enhanced datarate for GSM evolution (EDGE). The OFDMA may be implemented with a radiotechnology, such as institute of electrical and electronics engineers(IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, evolved UTRA(E-UTRA), and so on. IEEE 802.16m is an evolved version of IEEE 802.16eand provides backward compatibility with a system based on the IEEE802.16e. The UTRA is part of a universal mobile telecommunication system(UMTS). 3rd generation partnership project (3GPP) long term evolution(LTE) is part of an evolved UMTS (E-UMTS) using the E-UTRA. The 3GPP LTEuses the OFDMA in a downlink and uses the SC-FDMA in an uplink.LTE-advanced (LTE-A) is an evolution of the LTE.

5G NR is a successive technology of LTE-A corresponding to a newClean-slate type mobile communication system having the characteristicsof high performance, low latency, high availability, and so on. 5G NRmay use resources of all spectrum available for usage including lowfrequency bands of less than 1 GHz, middle frequency bands ranging from1 GHz to 10 GHz, high frequency (millimeter waves) of 24 GHz or more,and so on.

For clarity in the description, the following description will mostlyfocus on LTE-A or 5G NR. However, technical features according to anembodiment of the present disclosure will not be limited only to this.

FIG. 2 shows a structure of an NR system, in accordance with anembodiment of the present disclosure. The embodiment of FIG. 2 may becombined with various embodiments of the present disclosure.

Referring to FIG. 2, a next generation-radio access network (NG-RAN) mayinclude a BS 20 providing a UE 10 with a user plane and control planeprotocol termination. For example, the BS 20 may include a nextgeneration-Node B (gNB) and/or an evolved-NodeB (eNB). For example, theUE 10 may be fixed or mobile and may be referred to as other terms, suchas a mobile station (MS), a user terminal (UT), a subscriber station(SS), a mobile terminal (MT), wireless device, and so on. For example,the BS may be referred to as a fixed station which communicates with theUE 10 and may be referred to as other terms, such as a base transceiversystem (BTS), an access point (AP), and so on.

The embodiment of FIG. 2 exemplifies a case where only the gNB isincluded. The BSs 20 may be connected to one another via Xn interface.The BS 20 may be connected to one another via 5th generation (5G) corenetwork (5GC) and NG interface. More specifically, the BSs 20 may beconnected to an access and mobility management function (AMF) 30 viaNG-C interface, and may be connected to a user plane function (UPF) 30via NG-U interface.

FIG. 3 shows a functional division between an NG-RAN and a 5GC, inaccordance with an embodiment of the present disclosure.

Referring to FIG. 3, the gNB may provide functions, such as Inter CellRadio Resource Management (RRM), Radio Bearer (RB) control, ConnectionMobility Control, Radio Admission Control, Measurement Configuration &Provision, Dynamic Resource Allocation, and so on. An AMF may providefunctions, such as Non Access Stratum (NAS) security, idle statemobility processing, and so on. A UPF may provide functions, such asMobility Anchoring, Protocol Data Unit (PDU) processing, and so on. ASession Management Function (SMF) may provide functions, such as userequipment (UE) Internet Protocol (IP) address allocation, PDU sessioncontrol, and so on.

Layers of a radio interface protocol between the UE and the network canbe classified into a first layer (L1), a second layer (L2), and a thirdlayer (L3) based on the lower three layers of the open systeminterconnection (OSI) model that is well-known in the communicationsystem. Among them, a physical (PHY) layer belonging to the first layerprovides an information transfer service by using a physical channel,and a radio resource control (RRC) layer belonging to the third layerserves to control a radio resource between the UE and the network. Forthis, the RRC layer exchanges an RRC message between the UE and the BS.

FIG. 4 shows a radio protocol architecture, in accordance with anembodiment of the present disclosure. The embodiment of FIG. 4 may becombined with various embodiments of the present disclosure.Specifically, (a) of FIG. 4 shows a radio protocol architecture for auser plane, and (b) of FIG. 4 shows a radio protocol architecture for acontrol plane. The user plane corresponds to a protocol stack for userdata transmission, and the control plane corresponds to a protocol stackfor control signal transmission.

Referring to FIG. 4, a physical layer provides an upper layer with aninformation transfer service through a physical channel. The physicallayer is connected to a medium access control (MAC) layer which is anupper layer of the physical layer through a transport channel. Data istransferred between the MAC layer and the physical layer through thetransport channel. The transport channel is classified according to howand with what characteristics data is transmitted through a radiointerface.

Between different physical layers, i.e., a physical layer of atransmitter and a physical layer of a receiver, data are transferredthrough the physical channel. The physical channel is modulated using anorthogonal frequency division multiplexing (OFDM) scheme, and utilizestime and frequency as a radio resource.

The MAC layer provides services to a radio link control (RLC) layer,which is a higher layer of the MAC layer, via a logical channel. The MAClayer provides a function of mapping multiple logical channels tomultiple transport channels. The MAC layer also provides a function oflogical channel multiplexing by mapping multiple logical channels to asingle transport channel. The MAC layer provides data transfer servicesover logical channels.

The RLC layer performs concatenation, segmentation, and reassembly ofRadio Link Control Service Data Unit (RLC SDU). In order to ensurediverse quality of service (QoS) required by a radio bearer (RB), theRLC layer provides three types of operation modes, i.e., a transparentmode (TM), an unacknowledged mode (UM), and an acknowledged mode (AM).An AM RLC provides error correction through an automatic repeat request(ARQ).

A radio resource control (RRC) layer is defined only in the controlplane. The RRC layer serves to control the logical channel, thetransport channel, and the physical channel in association withconfiguration, reconfiguration and release of RBs. The RB is a logicalpath provided by the first layer (i.e., the physical layer or the PHYlayer) and the second layer (i.e., the MAC layer, the RLC layer, and thepacket data convergence protocol (PDCP) layer) for data delivery betweenthe UE and the network.

Functions of a packet data convergence protocol (PDCP) layer in the userplane include user data delivery, header compression, and ciphering.Functions of a PDCP layer in the control plane include control-planedata delivery and ciphering/integrity protection.

A service data adaptation protocol (SDAP) layer is defined only in auser plane. The SDAP layer performs mapping between a Quality of Service(QoS) flow and a data radio bearer (DRB) and QoS flow ID (QFI) markingin both DL and UL packets.

The configuration of the RB implies a process for specifying a radioprotocol layer and channel properties to provide a particular serviceand for determining respective detailed parameters and operations. TheRB can be classified into two types, i.e., a signaling RB (SRB) and adata RB (DRB). The SRB is used as a path for transmitting an RRC messagein the control plane. The DRB is used as a path for transmitting userdata in the user plane.

When an RRC connection is established between an RRC layer of the UE andan RRC layer of the E-UTRAN, the UE is in an RRC_CONNECTED state, and,otherwise, the UE may be in an RRC_IDLE state. In case of the NR, anRRC_INACTIVE state is additionally defined, and a UE being in theRRC_INACTIVE state may maintain its connection with a core networkwhereas its connection with the BS is released.

Data is transmitted from the network to the UE through a downlinktransport channel Examples of the downlink transport channel include abroadcast channel (BCH) for transmitting system information and adownlink-shared channel (SCH) for transmitting user traffic or controlmessages. Traffic of downlink multicast or broadcast services or thecontrol messages can be transmitted on the downlink-SCH or an additionaldownlink multicast channel (MCH). Data is transmitted from the UE to thenetwork through an uplink transport channel. Examples of the uplinktransport channel include a random access channel (RACH) fortransmitting an initial control message and an uplink SCH fortransmitting user traffic or control messages.

Examples of logical channels belonging to a higher channel of thetransport channel and mapped onto the transport channels include abroadcast channel (BCCH), a paging control channel (PCCH), a commoncontrol channel (CCCH), a multicast control channel (MCCH), a multicasttraffic channel (MTCH), etc.

The physical channel includes several OFDM symbols in a time domain andseveral sub-carriers in a frequency domain. One sub-frame includes aplurality of OFDM symbols in the time domain. A resource block is a unitof resource allocation, and consists of a plurality of OFDM symbols anda plurality of sub-carriers. Further, each subframe may use specificsub-carriers of specific OFDM symbols (e.g., a first OFDM symbol) of acorresponding subframe for a physical downlink control channel (PDCCH),i.e., an L1/L2 control channel A transmission time interval (TTI) is aunit time of subframe transmission.

FIG. 5 shows a structure of an NR system, in accordance with anembodiment of the present disclosure. The embodiment of FIG. 5 may becombined with various embodiments of the present disclosure.

Referring to FIG. 5, in the NR, a radio frame may be used for performinguplink and downlink transmission. A radio frame has a length of 10 msand may be defined to be configured of two half-frames (HFs). Ahalf-frame may include five lms subframes (SFs). A subframe (SF) may bedivided into one or more slots, and the number of slots within asubframe may be determined in accordance with subcarrier spacing (SCS).Each slot may include 12 or 14 OFDM(A) symbols according to a cyclicprefix (CP).

In case of using a normal CP, each slot may include 14 symbols. In caseof using an extended CP, each slot may include 12 symbols. Herein, asymbol may include an OFDM symbol (or CP-OFDM symbol) and a SingleCarrier-FDMA (SC-FDMA) symbol (or Discrete Fourier Transform-spread-OFDM(DFT-s-OFDM) symbol).

Table 1 shown below represents an example of a number of symbols perslot (Nslotsymb), a number slots per frame (Nframe,uslot), and a numberof slots per subframe (Nsubframe,uslot) in accordance with an SCSconfiguration (u), in a case where a normal CP is used.

TABLE 1 SCS (15*2^(u)) N^(slot) _(symb) N^(frame,u) _(slot)N^(subframe,u) _(slot)  15 KHz (u = 0) 14 10 1  30 KHz (u = 1) 14 20 2 60 KHz (u = 2) 14 40 4 120 KHz (u = 3) 14 80 8 240 KHz (u = 4) 14 16016

Table 2 shows an example of a number of symbols per slot, a number ofslots per frame, and a number of slots per subframe in accordance withthe SCS, in a case where an extended CP is used.

TABLE 2 SCS (15*2^(u)) N^(slot) _(symb) N^(frame,u) _(slot)N^(subframe,u) _(slot) 60 KHz (u = 2) 12 40 4

In an NR system, OFDM(A) numerologies (e.g., SCS, CP length, and so on)between multiple cells being integrate to one UE may be differentlyconfigured. Accordingly, a (absolute time) duration (or section) of atime resource (e.g., subframe, slot or TTI) (collectively referred to asa time unit (TU) for simplicity) being configured of the same number ofsymbols may be differently configured in the integrated cells.

In the NR, multiple numerologies or SCSs for supporting diverse 5Gservices may be supported. For example, in case an SCS is 15 kHz, a widearea of the conventional cellular bands may be supported, and, in casean SCS is 30 kHz/60 kHz a dense-urban, lower latency, wider carrierbandwidth may be supported. In case the SCS is 60 kHz or higher, abandwidth that is greater than 24.25 GHz may be used in order toovercome phase noise.

An NR frequency band may be defined as two different types of frequencyranges. The two different types of frequency ranges may be FR1 and FR2.The values of the frequency ranges may be changed (or varied), and, forexample, the two different types of frequency ranges may be as shownbelow in Table A3. Among the frequency ranges that are used in an NRsystem, FR1 may mean a “sub 6 GHz range”, and FR2 may mean an “above 6GHz range” and may also be referred to as a millimeter wave (mmW).

TABLE 3 Frequency Range Corresponding Subcarrier designation frequencyrange Spacing (SCS) FR1  450 MHz-6000 MHz 15, 30, 60 kHz FR2 24250MHz-52600 MHz 60, 120, 240 kHz

As described above, the values of the frequency ranges in the NR systemmay be changed (or varied). For example, as shown below in Table A4, FR1may include a band within a range of 410 MHz to 7125 MHz. Morespecifically, FR1 may include a frequency band of 6 GHz (or 5850, 5900,5925 MHz, and so on) and higher. For example, a frequency band of 6 GHz(or 5850, 5900, 5925 MHz, and so on) and higher being included in FR1mat include an unlicensed band. The unlicensed band may be used fordiverse purposes, e.g., the unlicensed band for vehicle-specificcommunication (e.g., automated driving).

TABLE 4 Frequency Range Corresponding Subcarrier designation frequencyrange Spacing (SCS) FR1  410 MHz-7125 MHz 15, 30, 60 kHz FR2 24250MHz-52600 MHz 60, 120, 240 kHz

FIG. 6 shows a structure of a slot of an NR frame, in accordance with anembodiment of the present disclosure.

Referring to FIG. 6, a slot includes a plurality of symbols in a timedomain. For example, in case of a normal CP, one slot may include 14symbols. However, in case of an extended CP, one slot may include 12symbols. Alternatively, in case of a normal CP, one slot may include 7symbols. However, in case of an extended CP, one slot may include 6symbols.

A carrier includes a plurality of subcarriers in a frequency domain. AResource Block (RB) may be defined as a plurality of consecutivesubcarriers (e.g., 12 subcarriers) in the frequency domain. A BandwidthPart (BWP) may be defined as a plurality of consecutive (Physical)Resource Blocks ((P)RBs) in the frequency domain, and the BWP maycorrespond to one numerology (e.g., SCS, CP length, and so on). Acarrier may include a maximum of N number BWPs (e.g., 5 BWPs). Datacommunication may be performed via an activated BWP. Each element may bereferred to as a Resource Element (RE) within a resource grid and onecomplex symbol may be mapped to each element.

Meanwhile, a radio interface between a UE and another UE or a radiointerface between the UE and a network may consist of an L1 layer, an L2layer, and an L3 layer. In various embodiments of the presentdisclosure, the L1 layer may imply a physical layer. In addition, forexample, the L2 layer may imply at least one of a MAC layer, an RLClayer, a PDCP layer, and an SDAP layer. In addition, for example, the L3layer may imply an RRC layer.

Hereinafter, a bandwidth part (BWP) and a carrier will be described.

The BWP may be a set of consecutive physical resource blocks (PRBs) in agiven numerology. The PRB may be selected from consecutive sub-sets ofcommon resource blocks (CRBs) for the given numerology on a givencarrier.

When using bandwidth adaptation (BA), a reception bandwidth andtransmission bandwidth of a UE are not necessarily as large as abandwidth of a cell, and the reception bandwidth and transmissionbandwidth of the BS may be adjusted. For example, a network/BS mayinform the UE of bandwidth adjustment. For example, the UE receiveinformation/configuration for bandwidth adjustment from the network/BS.In this case, the UE may perform bandwidth adjustment based on thereceived information/configuration. For example, the bandwidthadjustment may include an increase/decrease of the bandwidth, a positionchange of the bandwidth, or a change in subcarrier spacing of thebandwidth.

For example, the bandwidth may be decreased during a period in whichactivity is low to save power. For example, the position of thebandwidth may move in a frequency domain. For example, the position ofthe bandwidth may move in the frequency domain to increase schedulingflexibility. For example, the subcarrier spacing of the bandwidth may bechanged. For example, the subcarrier spacing of the bandwidth may bechanged to allow a different service. A subset of a total cell bandwidthof a cell may be called a bandwidth part (BWP). The BA may be performedwhen the BS/network configures the BWP to the UE and the BS/networkinforms the UE of the BWP currently in an active state among theconfigured BWPs.

For example, the BWP may be at least any one of an active BWP, aninitial BWP, and/or a default BWP. For example, the UE may not monitordownlink radio link quality in a DL BWP other than an active DL BWP on aprimary cell (PCell). For example, the UE may not receive PDCCH, PDSCH,or CSI-RS (excluding RRM) outside the active DL BWP. For example, the UEmay not trigger a channel state information (CSI) report for theinactive DL BWP. For example, the UE may not transmit PUCCH or PUSCHoutside an active UL BWP. For example, in a downlink case, the initialBWP may be given as a consecutive RB set for an RMSI CORESET (configuredby PBCH). For example, in an uplink case, the initial BWP may be givenby SIB for a random access procedure. For example, the default BWP maybe configured by a higher layer. For example, an initial value of thedefault BWP may be an initial DL BWP. For energy saving, if the UE failsto detect DCI during a specific period, the UE may switch the active BWPof the UE to the default BWP.

Meanwhile, the BWP may be defined for SL. The same SL BWP may be used intransmission and reception. For example, a transmitting UE may transmitan SL channel or an SL signal on a specific BWP, and a receiving UE mayreceive the SL channel or the SL signal on the specific BWP. In alicensed carrier, the SL BWP may be defined separately from a Uu BWP,and the SL BWP may have configuration signaling separate from the UuBWP. For example, the UE may receive a configuration for the SL BWP fromthe BS/network. The SL BWP may be (pre-)configured in a carrier withrespect to an out-of-coverage NR V2X UE and an RRC_IDLE UE. For the UEin the RRC_CONNECTED mode, at least one SL BWP may be activated in thecarrier.

FIG. 7 shows an example of a BWP, in accordance with an embodiment ofthe present disclosure. The embodiment of FIG. 7 may be combined withvarious embodiments of the present disclosure. It is assumed in theembodiment of FIG. 7 that the number of BWPs is 3.

Referring to FIG. 7, a common resource block (CRB) may be a carrierresource block numbered from one end of a carrier band to the other endthereof. In addition, the PRB may be a resource block numbered withineach BWP. A point A may indicate a common reference point for a resourceblock grid.

The BWP may be configured by a point A, an offset NstartBWP from thepoint A, and a bandwidth NsizeBWP. For example, the point A may be anexternal reference point of a PRB of a carrier in which a subcarrier 0of all numerologies (e.g., all numerologies supported by a network onthat carrier) is aligned. For example, the offset may be a PRB intervalbetween a lowest subcarrier and the point A in a given numerology. Forexample, the bandwidth may be the number of PRBs in the givennumerology.

Hereinafter, V2X or SL communication will be described.

FIG. 8 shows a radio protocol architecture for a SL communication, inaccordance with an embodiment of the present disclosure. The embodimentof FIG. 8 may be combined with various embodiments of the presentdisclosure. More specifically, (a) of FIG. 8 shows a user plane protocolstack, and (b) of FIG. 8 shows a control plane protocol stack.

Hereinafter, a sidelink synchronization signal (SLSS) andsynchronization information will be described.

The SLSS may include a primary sidelink synchronization signal (PSSS)and a secondary sidelink synchronization signal (SSSS), as anSL-specific sequence. The PSSS may be referred to as a sidelink primarysynchronization signal (S-PSS), and the SSSS may be referred to as asidelink secondary synchronization signal (S-SSS). For example,length-127 M-sequences may be used for the S-PSS, and length-127 goldsequences may be used for the S-SSS. For example, a UE may use the S-PSSfor initial signal detection and for synchronization acquisition. Forexample, the UE may use the S-PSS and the S-SSS for acquisition ofdetailed synchronization and for detection of a synchronization signalID.

A physical sidelink broadcast channel (PSBCH) may be a (broadcast)channel for transmitting default (system) information which must befirst known by the UE before SL signal transmission/reception. Forexample, the default information may be information related to SLSS, aduplex mode (DM), a time division duplex (TDD) uplink/downlink (UL/DL)configuration, information related to a resource pool, a type of anapplication related to the SLSS, a subframe offset, broadcastinformation, or the like. For example, for evaluation of PSBCHperformance, in NR V2X, a payload size of the PSBCH may be 56 bitsincluding 24-bit CRC.

The S-PSS, the S-SSS, and the PSBCH may be included in a block format(e.g., SL synchronization signal (SS)/PSBCH block, hereinafter,sidelink-synchronization signal block (S-SSB)) supporting periodicaltransmission. The S-SSB may have the same numerology (i.e., SCS and CPlength) as a physical sidelink control channel (PSCCH)/physical sidelinkshared channel (PSSCH) in a carrier, and a transmission bandwidth mayexist within a (pre-)configured sidelink (SL) BWP. For example, theS-SSB may have a bandwidth of 11 resource blocks (RBs). For example, thePSBCH may exist across 11 RBs. In addition, a frequency position of theS-SSB may be (pre-)configured. Accordingly, the UE does not have toperform hypothesis detection at frequency to discover the S-SSB in thecarrier.

FIG. 9 shows a UE performing V2X or SL communication, in accordance withan embodiment of the present disclosure. The embodiment of FIG. 9 may becombined with various embodiments of the present disclosure.

Referring to FIG. 9, in V2X or SL communication, the term ‘UE’ maygenerally imply a UE of a user. However, if a network equipment such asa BS transmits/receives a signal according to a communication schemebetween UEs, the BS may also be regarded as a sort of the UE. Forexample, a UE 1 may be a first apparatus 100, and a UE 2 may be a secondapparatus 200.

For example, the UE 1 may select a resource unit corresponding to aspecific resource in a resource pool which implies a set of series ofresources. In addition, the UE 1 may transmit an SL signal by using theresource unit. For example, a resource pool in which the UE 1 is capableof transmitting a signal may be configured to the UE 2 which is areceiving UE, and the signal of the UE 1 may be detected in the resourcepool.

Herein, if the UE 1 is within a connectivity range of the BS, the BS mayinform the UE 1 of the resource pool. Otherwise, if the UE 1 is out ofthe connectivity range of the BS, another UE may inform the UE 1 of theresource pool, or the UE 1 may use a pre-configured resource pool.

In general, the resource pool may be configured in unit of a pluralityof resources, and each UE may select a unit of one or a plurality ofresources to use it in SL signal transmission thereof.

Hereinafter, resource allocation in SL will be described.

FIG. 10 shows a procedure of performing V2X or SL communication by a UEbased on a transmission mode, in accordance with an embodiment of thepresent disclosure. The embodiment of FIG. 10 may be combined withvarious embodiments of the present disclosure. In various embodiments ofthe present disclosure, the transmission mode may be called a mode or aresource allocation mode. Hereinafter, for convenience of explanation,in LTE, the transmission mode may be called an LTE transmission mode. InNR, the transmission mode may be called an NR resource allocation mode.

For example, (a) of FIG. 10 shows a UE operation related to an LTEtransmission mode 1 or an LTE transmission mode 3. Alternatively, forexample, (a) of FIG. 10 shows a UE operation related to an NR resourceallocation mode 1. For example, the LTE transmission mode 1 may beapplied to general SL communication, and the LTE transmission mode 3 maybe applied to V2X communication.

For example, (b) of FIG. 10 shows a UE operation related to an LTEtransmission mode 2 or an LTE transmission mode 4. Alternatively, forexample, (b) of FIG. 10 shows a UE operation related to an NR resourceallocation mode 2.

Referring to (a) of FIG. 10, in the LTE transmission mode 1, the LTEtransmission mode 3, or the NR resource allocation mode 1, a BS mayschedule an SL resource to be used by the UE for SL transmission. Forexample, the BS may perform resource scheduling to a UE 1 through aPDCCH (more specifically, downlink control information (DCI)), and theUE 1 may perform V2X or SL communication with respect to a UE 2according to the resource scheduling. For example, the UE 1 may transmita sidelink control information (SCI) to the UE 2 through a physicalsidelink control channel (PSCCH), and thereafter transmit data based onthe SCI to the UE 2 through a physical sidelink shared channel (PSSCH).

Referring to (b) of FIG. 10, in the LTE transmission mode 2, the LTEtransmission mode 4, or the NR resource allocation mode 2, the UE maydetermine an SL transmission resource within an SL resource configuredby a BS/network or a pre-configured SL resource. For example, theconfigured SL resource or the pre-configured SL resource may be aresource pool. For example, the UE may autonomously select or schedule aresource for SL transmission. For example, the UE may perform SLcommunication by autonomously selecting a resource within a configuredresource pool. For example, the UE may autonomously select a resourcewithin a selective window by performing a sensing and resource(re)selection procedure. For example, the sensing may be performed inunit of subchannels. In addition, the UE 1 which has autonomouslyselected the resource within the resource pool may transmit the SCI tothe UE 2 through a PSCCH, and thereafter may transmit data based on theSCI to the UE 2 through a PSSCH.

FIG. 11 show three cast types, in accordance with an embodiment of thepresent disclosure. The embodiment of FIG. 11 may be combined withvarious embodiments of the present disclosure. Specifically, (a) of FIG.11 shows broadcast-type SL communication, (b) of FIG. 11 shows unicasttype-SL communication, and (c) of FIG. 11 shows groupcast-type SLcommunication. In case of the unicast-type SL communication, a UE mayperform one-to-one communication with respect to another UE. In case ofthe groupcast-type SL transmission, the UE may perform SL communicationwith respect to one or more UEs in a group to which the UE belongs. Invarious embodiments of the present disclosure, SL groupcastcommunication may be replaced with SL multicast communication, SLone-to-many communication, or the like.

Meanwhile, in sidelink communication, a UE may need to effectivelyselect a resource for sidelink transmission. Hereinafter, a method inwhich a UE effectively selects a resource for sidelink transmission andan apparatus supporting the method will be described according tovarious embodiments of the present disclosure. In various embodiments ofthe present disclosure, the sidelink communication may include V2Xcommunication.

At least one scheme proposed according to various embodiments of thepresent disclosure may be applied to at least any one of unicastcommunication, groupcast communication, and/or broadcast communication.

At least one method proposed according to various embodiment of thepresent embodiment may apply not only to sidelink communication or V2Xcommunication based on a PC5 interface or an SL interface (e.g., PSCCH,PSSCH, PSBCH, PSSS/SSSS, etc.) or V2X communication but also to sidelinkcommunication or V2X communication based on a Uu interface (e.g., PUSCH,PDSCH, PDCCH, PUCCH, etc.).

In various embodiments of the present disclosure, a receiving operationof a UE may include a decoding operation and/or receiving operation of asidelink channel and/or sidelink signal (e.g., PSCCH, PSSCH, PSFCH,PSBCH, PSSS/SSSS, etc.). The receiving operation of the UE may include adecoding operation and/or receiving operation of a WAN DL channel and/ora WAN DL signal (e.g., PDCCH, PDSCH, PSS/SSS, etc.). The receivingoperation of the UE may include a sensing operation and/or a CBRmeasurement operation. In various embodiments of the present disclosure,the sensing operation of the UE may include a PSSCH-RSRP measurementoperation based on a PSSCH DM-RS sequence, a PSSCH-RSRP measurementoperation based on a PSSCH DM-RS sequence scheduled by a PSCCHsuccessfully decoded by the UE, a sidelink RSSU (S-RSSI) measurementoperation, and an S-RSSI measurement operation based on a V2X resourcepool related subchannel. In various embodiments of the disclosure, atransmitting operation of the UE may include a transmitting operation ofa sidelink channel and/or a sidelink signal (e.g., PSCCH, PSSCH, PSFCH,PSBCH, PSSS/SSSS. etc.). The transmitting operation of the UE mayinclude a transmitting operation of a WAN UL channel and/or a WAN ULsignal (e.g., PUSCH, PUCCH, SRS, etc.). In various embodiments of thepresent disclosure, a synchronization signal may include SLSS and/orPSBCH.

In various embodiments of the present disclosure, a configuration mayinclude signaling, signaling from a network, a configuration from thenetwork, and/or a pre-configuration from the network. In variousembodiments of the present disclosure, a definition may includesignaling, signaling from a network, a configuration form the network,and/or a pre-configuration from the network. In various embodiment ofthe present disclosure, a designation may include signaling, signalingfrom a network, a configuration from the network, and/or apre-configuration from the network.

In various embodiments of the present disclosure, a ProSe per packetpriority (PPPP) may be replaced with a ProSe per packet reliability(PPPR), and the PPPR may be replaced with the PPPP. For example, it maymean that the smaller the PPPP value, the higher the priority, and thatthe greater the PPPP value, the lower the priority. For example, it maymean that the smaller the PPPR value, the higher the reliability, andthat the greater the PPPR value, the lower the reliability. For example,a PPPP value related to a service, packet, or message related to a highpriority may be smaller than a PPPP value related to a service, packet,or message related to a low priority. For example, a PPPR value relatedto a service, packet, or message related to a high reliability may besmaller than a PPPR value related to a service, packet, or messagerelated to a low reliability

In various embodiments of the present disclosure, a session may includeat least any one of a unicast session (e.g., unicast session forsidelink), a groupcast/multicast session (e.g., groupcast/multicastsession for sidelink), and/or a broadcast session (e.g., broadcastsession for sidelink).

In various embodiments of the present disclosure, a carrier may beinterpreted as at least any one of a BWP and/or a resource pool. Forexample, the carrier may include at least any one of the BWP and/or theresource pool. For example, the carrier may include one or more BWPs.For example, the BWP may include one or more resource pools.

Hereinafter, an SL synchronization signal (Sidelink SynchronizationSignal, SLSS) and synchronization information will be described.

The SLSS is an SL-specific sequence and may include a Primary SidelinkSynchronization Signal (PSSS) and a Secondary Sidelink SynchronizationSignal (SSSS). The PSSS may be referred to as a Sidelink PrimarySynchronization Signal (S-PSS), and the SSSS may be referred to as aSidelink Secondary Synchronization Signal (S-SSS). For example,length-127 M-sequences may be used for S-PSS and length-127 Goldsequences may be used for S-SSS. For example, the terminal may detect aninitial signal using S-PSS and may obtain synchronization. For example,the UE may obtain detailed synchronization using S-PSS and S-SSS, andmay detect a synchronization signal ID.

PSBCH (Physical Sidelink Broadcast Channel) may be a (broadcast) channelthrough which basic (system) information that the terminal needs to knowfirst before transmission and reception of SL signals is transmitted.For example, the basic information may be information related to SLSS,duplex mode (Duplex Mode, DM), TDD UL/DL (Time Division DuplexUplink/Downlink) configuration, resource pool related information, typeof application related to SLSS, a subframe offset, broadcastinformation, or the like. For example, for evaluation of PSBCHperformance, in NR V2X, the payload size of PSBCH may be 56 bitsincluding a CRC of 24 bits.

S-PSS, S-SSS, and PSBCH may be included in a block format supportingperiodic transmission (e.g., SLSS (Synchronization Signal)/PSBCH block,hereinafter S-SSB (Sidelink-Synchronization Signal Block)). The S-SSBmay have the same numerology (ie, SCS and CP length) as a PhysicalSidelink Control Channel (PSCCH)/Physical Sidelink Shared Channel(PSSCH) in the carrier, and the transmission bandwidth may be located in(pre)configured SL BWP. For example, the bandwidth of the S-SSB may be11 resource blocks (RBs). For example, the PSBCH may be located through11 RBs. And, the frequency position of the S-SSB may be (pre)configured. Therefore, the terminal does not need to perform hypothesisdetection in frequency to discover the S-SSB in the carrier.

Meanwhile, in the NR SL system, a plurality of numerologies havingdifferent SCS and/or CP lengths may be supported. In this case, as theSCS increases, the length of the time resource for the transmittingterminal to transmit the S-SSB may be shortened. Accordingly, thecoverage of the S-SSB may be reduced. Accordingly, in order to guaranteethe coverage of the S-SSB, the transmitting terminal may transmit one ormore S-SSBs to the receiving terminal within one S-SSB transmissionperiod according to the SCS. For example, the number of S-SSBs that thetransmitting terminal transmits to the receiving terminal within oneS-SSB transmission period may be pre-configured or configured in thetransmitting terminal. For example, the S-SSB transmission period may be160 ms. For example, for all SCSs, an S-SSB transmission period of 160ms may be supported.

For example, when the SCS is 15 kHz in FR1, the transmitting terminalmay transmit one or two S-SSBs to the receiving terminal within oneS-SSB transmission period. For example, when the SCS is 30 kHz in FR1,the transmitting terminal may transmit one or two S-SSBs to thereceiving terminal within one S-SSB transmission period. For example,when the SCS is 60 kHz in FR1, the transmitting terminal may transmitone, two, or four S-SSBs to the receiving terminal within one S-SSBtransmission period.

For example, if the SCS is 60 kHz in FR2, the transmitting terminal maytransmit 1, 2, 4, 8, 16 or 32 S-SSBs to the receiving terminal withinone S-SSB transmission period. For example, when SCS is 120 kHz in FR2,the transmitting terminal may transmit 1, 2, 4, 8, 16, 32 or 64 S-SSBsto the receiving terminal within one S-SSB transmission period.

Meanwhile, when the SCS is 60 kHz, two types of CPs may be supported.Also, the structure of the S-SSB transmitted from the transmittingterminal to the receiving terminal may be different according to the CPtype. For example, the CP type may be a Normal CP (NCP) or an ExtendedCP (ECP). Specifically, for example, when the CP type is NCP, the numberof symbols for mapping the PSBCH in the S-SSB transmitted by thetransmitting terminal may be 9 or 8. On the other hand, for example,when the CP type is ECP, the number of symbols for mapping the PSBCH inthe S-SSB transmitted by the transmitting terminal may be 7 or 6. Forexample, the PSBCH may be mapped to the first symbol in the S-SSBtransmitted by the transmitting terminal. For example, the receivingterminal receiving the S-SSB may perform an automatic gain control (AGC)operation in the first symbol period of the S-SSB. Hereinafter, examplesof the structure of the S-SSB will be discussed in FIG. 12.

FIG. 12 shows examples of the structure of an S-SSB.

(a) of FIG. 12 illustrates the structure of an S-SSB when the CP type isNCP according to an embodiment of the present disclosure. For example,when the CP type is NCP, the structure of the S-SSB, that is, the orderof symbols to which S-PSS, S-SSS, and PSBCH are mapped in the S-SSBtransmitted by the transmitting terminal may refer to (a) of FIG. 12(a).

(b) of FIG. 12 illustrates the structure of an S-SSB when the CP type isECP according to an embodiment of the present disclosure.

For example, when the CP type is ECP, the number of symbols for whichthe transmitting terminal maps the PSBCH after the S-SSS in the S-SSBmay be 6, unlike (a) of FIG. 12. Accordingly, the coverage of the S-SSBmay be different depending on whether the CP type is NCP or ECP.

Meanwhile, each SLSS may have an SL synchronization identifier (SidelinkSynchronization Identifier, SLSS ID).

For example, in the case of LTE SL or LTE V2X, the value of the SLSS IDmay be defined based on a combination of two different S-PSS sequencesand 168 different S-SSS sequences. For example, the number of SLSS IDsmay be 336. For example, the value of the SLSS ID may be any one of 0 to335.

For example, in the case of NR SL or NR V2X, the value of the SLSS IDmay be defined based on a combination of two different S-PSS sequencesand 336 different S-SSS sequences. For example, the number of SLSS IDsmay be 672. For example, the value of the SLSS ID may be any one of 0 to671. For example, among two different S-PSSs, one S-PSS may beassociated with in-coverage, and the other S-PSS may be associated without-of-coverage. For example, SLSS IDs of 0 to 335 may be used inin-coverage, and SLSS IDs of 336 to 671 may be used in out-coverage.

Meanwhile, the transmitting terminal needs to optimize the transmissionpower according to the characteristics of each signal constituting theS-SSB in order to improve the S-SSB reception performance of thereceiving terminal. For example, according to the peak to average powerratio (PAPR) of each signal constituting the S-SSB, the transmittingterminal may determine a maximum power reduction (MPR) value for eachsignal. For example, if the PAPR value is different between the S-PSSand S-SSS constituting the S-SSB, in order to improve the S-SSBreception performance of the receiving terminal, the transmittingterminal may apply an optimal MPR value to each of transmissions of theS-PSS and the S-SSS. Also, for example, in order for the transmittingterminal to amplify each signal, a transition period may be applied. Thetransition period may reserve a time required for the transmitteramplifier of the transmitting terminal to perform a normal operation atthe boundary where the transmission power of the transmitting terminalvaries. For example, in the case of FR1, the transition period may be 10us. For example, in the case of FR2, the transition period may be 5 us.For example, a search window for the receiving terminal to detect theS-PSS may be 80 ms and/or 160 ms.

In the Uu link of the RAT according to an embodiment, the base stationand the terminal may transmit and receive DL, UL, FL (Flexible) slots orsymbols based on higher layer signaling. More specifically, the slotformat structure based on the higher layer signaling may be provided ascell common information or may be provided as UE dedicated. In addition,for an FL symbol of a slot format structure based on higher layersignaling of RAT according to an embodiment, DL, UL, or FL may beindicated again through DCI (with CRC scrambled by SFI-RNTI). When onlythe semi-static slot format is configured (including the case where theDCI-based slot format is missing), the terminal may perform a monitoringof PDCCH in the area configured to DL or FL, higher layer configurationPDSCH and/or measurement. In addition, DL reception or UL transmissionmay be performed by dynamic scheduling. When the terminal receives aDCI-based slot format, the corresponding slot may be used as DL or UL byDCI-based scheduling, and the terminal may perform reception ortransmission. When the terminal receives the DCI-based slot format,higher layer configuration DL reception or UL transmission is possibleonly when configured as DL or UL, respectively, and may be canceled inother cases. In the case of the SSB for the Uu link, a DL slot or a DLsymbol may always be guaranteed for a transmission position.

In the RAT according to an embodiment, in the case of an in-coverage UE,SL transmission may be expected for UL and/or FL symbols/slots, whichmay also include SSB for SL (SL-SSB). More specifically, the UL and/orFL symbols/slots may be based on higher layer signaling (i.e, common tocells). More specifically, in the UL and/or FL symbol/slot, a symbol orslot for sidelink transmission (hereinafter, SL symbol group or SL slot)may be more restricted (through higher layer signaling) (hereinafter, SLslot/symbol). In the above situation, a transmission/receptionopportunity may be lost or transmission/reception delay may occur insome channels related to sidelink transmission due to the slot format.In order to avoid the above problem, a method of configuring an SL slotor an SL symbol group for a region in which an SL-SSB is transmitted maybe considered, but the method may limit scheduling flexibility for theUu link.

In an embodiment, a method of transmitting the SL-SSB based on a slotformat may be considered. If the position and configuration in the slotof the SL-SSB are fixed regardless of the slot format, the time domainin which the SL-SSB is transmitted is a slot format based on cell-commonand/or UE-only higher layer signaling. The indicator may be in a form(eg, UL or FL symbol) that guarantees SL transmission. In this case, theUL resource may be excessively configured more than necessary, which maylead to DL throughput loss. Or, when the SL-SSB overlaps the DL symboland/or the FL symbol by the slot format indicator based on cell-commonand/or UE-only higher layer signaling, SL-SSB transmission/reception maybe not performed. More specifically, the method of configuring thetransmission timing of the SL-SSB is a method of applying a periodand/or offset in a logical domain by rearranging slots in which SLtransmission is possible or SL-SSB transmission is possible. It may beto avoid collision between SL-SSB and DL or FL symbols. Dynamic SFI (viaDCI format) may be to configure DL/UL/FL (flexible) again for an FL slotor symbol based on higher layer signaling, and it may be that theterminal does not expect DL or FL symbol configuration for an area inwhich SL-SSB is transmitted or may be transmitted. In the case of theabove method, there may be an advantage in terms of guaranteeing thetransmission of the SL-SSB, but may cause latency for the Uu linktransmission depending on the traffic type. As part of a method forbypassing the above scheme, it may be considered to skip transmission ofthe SL-SSB according to the dynamic SFI configuration (e.g., a part ofthe transmission region of the SL-SSB is configured to DL or FLsymbols).

In another embodiment, a form in which the position and/or configurationin the slot of the SL-SSB varies according to the slot format may beconsidered. For example, depending on the slot format, the position inthe slot of the SL-SSB may be close to the beginning of a slot or closeto the end of a slot. The following shows a more specific example. Thefollowing examples may be combined with each other.

In one example, the starting symbol index and the ending symbol index inthe slot for the SL-SSB may be fixed, and depending on the slot format(based on higher layer signaling and/or DCI indication), a part of theSL-SSB may be dropped for some symbols (e.g., a region overlapping witha DL symbol or an FL symbol). More specifically, when DMRS of PSS, SSSand/or PSBCH is dropped, the entire SL-SSB may be dropped.Alternatively, it may be that the UE does not expect at least DMRS ofPSS, SSS and/or PSBCH to overlap with DL symbols and/or FL symbols.Through this example, implementation complexity may be reduced bypreventing the positions of the PSS and/or SSS from being changed duringthe synchronization procedure. When a symbol group corresponding to themiddle of the SL-SSB is dropped, a transient time and/or AGC pernon-contiguous symbol group may be required, and all or part of a symbolgroup of the SL-SSB may be dropped additionally.

In another example, according to the slot format (based on higher layersignaling and/or DCI indication), a starting symbol index for SL-SSBand/or length (of the SL-SSB related symbol) may be changed so as not tooverlap with the DL symbol or the FL symbol. More specifically, achangeable location may be pre-defined or pre-configured. If the overlapwith the DL symbol or the FL symbol may not be avoided only by movingthe position of the SL-SSB, all or part of the SL-SSB may be dropped.More specifically, when overlapping of the transmission of DMRS of PSS,SSS and/or PSBCH in SL-SSB with DL symbols or FL symbols may not beavoided, the entire SL-SSB may be dropped.

With respect to the degree of variability of the SL-SSB (eg, theposition in the slot of the SL-SSB), when the transmitting UE and thereceiving UE successfully receive the SFI from the same cell, theposition of the SL-SSB may be clearly recognized. However, when thetransmitting UE and the receiving UE correspond to different cells, orwhen the out-of-coverage UE performs blind decoding (BD) for SL-SSB, thetransmitting UE and the receiving UE needs to separately receive thecorresponding change information. Through this method, the receiving UEmay recognize a slot boundary based on the SL-SSB. The following showsmore specific examples of a method for the transmitting UE to indicateto the receiving UE the location information of the SL-SSB (e.g., astart/end symbol index or a symbol offset from a reference SL-SSB,etc.). The following examples may be combined with each other.

In one example, location information of the SL-SSB may be included in SLsystem information included in the PSBCH. In this example, the relativeposition between the PSS and/or the SSS and the PSBCH may be fixed. Whencoverage is determined through combining between a plurality of SL-SSBs,the location information of the SL-SSB indicated by the SL systeminformation may be location information of the current SL-SSB, theprevious SL-SSB and/or the next SL-SSB.

In another example, location information of the SL-SSB may be indicatedbased on the DMRS of the PSBCH. More specifically, the locationinformation of the SL-SSB may be indicated based on a sequence indexand/or a scrambling sequence for the DMRS of the PSBCH.

In another example, a combination of PSS and/or SSS may be determineddifferently according to a slot position of the SL-SSB. Morespecifically, based on the additional parameter, the sequence of the PSSand/or the SSS may be changed according to the location of the SL-SSB.In this example, a BD for synchronization may be generated, and in orderto prevent this, the configuration method for the SLID may be changedaccording to the location of the SL-SSB.

Hereinafter, a method of relaying an SL-SSB according to an embodimentwill be described.

In the NR Uu link according to an embodiment, the period and/or offsetof the SSB may be changed through higher layer signaling, and it is usedfor rate-matching in consideration of multiplexing between differentchannels. The SSB index for the operation may be transmitted to the UE.More specifically, the UE may receive the SSB index from the basestation, and based on the SSB index, when the DL channel overlaps thecorresponding SSB, some channels may not be received/transmitted or ratematching may be performed. In the Uu link, a default setting (e.g., a 20msec period) may be assumed for the SSB configuration during initialaccess.

In LTE SL according to an embodiment, when a UE receives an SL-SS fromanother UE, the UE may relay the SL-SS to another UE, and thetransmission location of the SL-SS for relaying may be derived based oninformation received from the PSBCH. More specifically, the UE receivingthe SL-SS through the first resource may relay the SL-SS through thesecond resource, and conversely, the UE receiving the SL-SS through thesecond resource may relay the SL-SS through the first resource. The UEmay recognize whether the SL-SS is received through which resource,based on information transmitted from the PSBCH.

The RAT according to an embodiment may also perform SL-SSB relaying bythe UE, but SL-SSB resources for relaying may not be available dependingon the slot format. In addition, when receiving the SL-SSB from the UE,a method of configuring the dynamically changed SL-SSB resource inconsideration of the BD may not be suitable.

Considering the above situation, in one example, it may be considered toincrease the amount of resources capable of relaying, and in anotherexample, the UE may perform the SL-SSB relaying based on a specificresource (for example, the fastest resource in time among resourcescapable of transmitting SL-SSB even after applying the slot format (in acircumstance that the SL-SSB does not overlap with symbols of DL orflexible (FL)) (for example, the fastest resource in time among theresources available for SSB transmission), or a resource (or apre-configured resource unit) with the lowest sensing result for ameasurement metric such as RSSI or a resource (or a pre-configuredresource unit) whose sensing result for a measurement metric such asRSSI is lower than a specific threshold.

In another example, the SL-SSB may indicate resource information forrelaying. More specifically, resource information for relaying may beindicated (or transmitted) through the PSBCH, and the transmitting UEmay select a resource capable of SL-SSB transmission in consideration ofthe slot format. Considering the complexity of receiving the SL-SSB fromthe receiving UE, the amount of resources that may be indicated may belimited, and the resources may be predefined or preconfigured (orpreconfigured).

FIG. 13 is a flowchart illustrating an operation of a first apparatusaccording to an embodiment of the present disclosure.

The operations disclosed in the flowchart of FIG. 13 may be performed incombination with various embodiments of the present disclosure. In oneexample, the operations disclosed in the flowchart of FIG. 13 may beperformed based on at least one of the apparatuses illustrated in FIGS.14 to 19. In one example, the first apparatus of FIG. 13 may correspondto the first wireless device 100 of FIG. 15 to be described later. Inanother example, the first apparatus of FIG. 13 may correspond to thesecond wireless device 200 of FIG. 15 to be described later.

In step S1310, the first apparatus according to an embodiment maydetermine a first resource that is considered to be possible to transmitthe first SL-SSB. In one example, the first resource may indicate aresource considered to be capable of SL-SSB transmission or SL-SSBrelaying. In another example, the first resource may indicate a resourcethat is considered capable of SL-SSB transmission or SL-SSB relayingbefore considering the slot format.

In step S1320, the first apparatus according to an embodiment maytransmit the first SL-SSB to the second apparatus based on the firstresource.

The first apparatus according to an embodiment may receive a secondSL-SSB from a third apparatus. Here, the first apparatus according to anexample may transmit the first SL-SSB to the second apparatus based onthe received second SL-SSB and the first resource. The transmitting ofthe first SL-SSB to the second apparatus based on the received secondSL-SSB and the first resource by the first apparatus according to amexample may include: determining a second resource among the firstresource based on a slot format of the first SL-SSB and transmitting thefirst SL-SSB to the second apparatus based on the second resrouce. Here,the second resource according to an example may represent a resourcethat overlaps with an uplink (UL) resource or a sidelink (SL) resourceamong the first resource. Alternatively, the second resource mayindicate a resource that does not overlap with a downlink (DL) resourceor a flexible (FL) resource based on a slot format among the firstresource. The transmitting of the first SL-SSB to the second apparatusbased on the second resource by the first apparatus according to anexample may include: transmitting the first SL-SSB to the secondapparatus through a resource of a pre-configured resource unit that mostprecedes in time among the second resource. The transmitting of thefirst SL-SSB to the second apparatus based on the second resource by thefirst apparatus according to an example may include: deriving a sensingresource among the second resource based on a sensing operationconsidering a pre-configured resource unit and transmitting the firstSL-SSB to the second apparatus through the sensing resource. In anexample, a reference signal strength indication (RSSI) value may besmallest among a plurality of RSSI values determined based on aplurality of resources of the pre-configured resource unit included inthe second resource. In an example, a RSSI value determined based on thesensing resource may be smaller than a pre-configured threshold, and thesensing resource may be the most advanced in time among a plurality ofresources having an RSSI value smaller than the pre-configuredthreshold, and the plurality of resources may be based on the previouslyconfigured resource unit. In an example, the second SL-SSB may includefirst resource indication information related to a physical sidelinkbroadcast channel (PSBCH), and the first resource may be determinedbased on the first resource indication information.

The transmitting of the first SL-SSB to the second apparatus by a firstapparatus according to another embodiment may include: determining athird resource based on a slot format of the first SL-SSB among thefirst resource and transmitting the first SL-SSB to the second apparatusbased on the third resource. In an example, the first resource may bedetermined based on a starting symbol index and an ending symbol indexin a slot for the first SL-SSB, and the third resource may represent aresource that overlaps with an UL resource or an SL resource based onthe slot format among the first resource. In an example, the firstresource may be determined based on a starting symbol index and a firstresource length in a slot for the first SL-SSB, and the third resourcemay represent a resource that overlaps with an UL resource or an SLresource based on the slot format among the first resource.Alternatively, the third resource may represent a resource that does notoverlap with a DL resource or a FL resource based on a slot format amongthe first resource. In one example, the first resource may be determinedbased on a starting symbol index and a first resource length within aslot for the first SL-SSB, and the third resource may represent aresource overlapping with a UL resource or an SL resource based on theslot format among the first resource. The transmitting of the firstSL-SSB to the second apparatus by the first apparatus according to anexample may include: transmitting location information of the firstSL-SSB to the second apparatus through a PSBCH. In an example, thelocation information of the first SL-SSB may be included in SL systeminformation related to the PSBCH or a demodulation reference signal(DMRS) related to the PSBCH.

According to an embodiment of the present disclosure, a first apparatustransmitting a sidelink-synchronization signal block (SL-SSB) may beprovided. The first apparatus may include at least one memory storinginstructions, at least one transceiver and at least one processorconnecting the at least one memory and the at least one transceiver,wherein the at least one processor is configured to: determine a firstresource considered capable of transmitting a first SL-SSB, and controlthe at least one transceiver to transmit the first SL-SSB to a secondapparatus based on the first resource.

According to an embodiment of the present disclosure, an apparatuscontrolling a first terminal (or a chip(set)) may be provided. Theapparatus may include at least one processor and at least one computermemory operably coupled by the at least one processor and storinginstructions, wherein, by the at least one processor executing theinstructions, the first terminal is configured to: determine a firstresource considered capable of transmitting a first SL-SSB, and transmitthe first SL-SSB to a second apparatus based on the first resource.

In one example, the first terminal of the embodiment may represent thefirst apparatus described throughout the present disclosure. In oneexample, the at least one processor, each of the at least one memory,and the like in the apparatus for controlling the first terminal may beimplemented as a separate sub chip, or at least two or more componentsmay be implemented through a sub-chip.

According to an embodiment of the present disclosure, a non-transitorycomputer-readable storage medium storing instructions may be provided.Based on the instructions being executed by at least one processor ofthe non-transitory computer readable storage medium: a first resourcethat is considered to be possible to transmit a first SL-SSB isdetermined by the first apparatus, and by the first apparatus, based onthe first resource, the first SL-SSB is transmitted to the secondapparatus.

According to an embodiment of the present disclosure, a second apparatusreceiving a sidelink-synchronization signal block (SL-SSB) may beprovided. The second apparatus may include at least one memory storinginstructions, at least one transceiver and at least one processorconnecting the at least one memory and the at least one transceiver,wherein the at least one processor is configured to: control the atleast one transceiver to receive the SL-SSB from the first apparatus. Inan example, the SL-SSB may be received through a resource determinedbased on a slot format.

Various embodiments of the present disclosure may be independentlyimplemented. Alternatively, the various embodiments of the presentdisclosure may be implemented by being combined or merged. For example,although the various embodiments of the present disclosure have beendescribed based on the 3GPP LTE system for convenience of explanation,the various embodiments of the present disclosure may also be extendedlyapplied to another system other than the 3GPP LTE system. For example,the various embodiments of the present disclosure may also be used in anuplink or downlink case without being limited only to directcommunication between terminals. In this case, a base station, a relaynode, or the like may use the proposed method according to variousembodiments of the present disclosure. For example, it may be definedthat information on whether to apply the method according to variousembodiments of the present disclosure is reported by the base station tothe terminal or by a transmitting terminal to a receiving terminalthrough pre-defined signaling (e.g., physical layer signaling or higherlayer signaling). For example, it may be defined that information on arule according to various embodiments of the present disclosure isreported by the base station to the terminal or by a transmittingterminal to a receiving terminal through pre-defined signaling (e.g.,physical layer signaling or higher layer signaling). For example, someembodiments among various embodiments of the present disclosure may beapplied limitedly only to a resource allocation mode 1. For example,some embodiments among various embodiments of the present disclosure maybe applied limitedly only to a resource allocation mode 2.

Hereinafter, an apparatus to which various embodiments of the presentdisclosure can be applied will be described.

The various descriptions, functions, procedures, proposals, methods,and/or operational flowcharts of the present disclosure described inthis document may be applied to, without being limited to, a variety offields requiring wireless communication/connection (e.g., 5G) betweendevices.

Hereinafter, a description will be given in more detail with referenceto the drawings. In the following drawings/description, the samereference symbols may denote the same or corresponding hardware blocks,software blocks, or functional blocks unless described otherwise.

FIG. 14 shows a communication system 1, in accordance with an embodimentof the present disclosure.

Referring to FIG. 14, a communication system 1 to which variousembodiments of the present disclosure are applied includes wirelessdevices, Base Stations (BSs), and a network. Herein, the wirelessdevices represent devices performing communication using Radio AccessTechnology (RAT) (e.g., 5G New RAT (NR)) or Long-Term Evolution (LTE))and may be referred to as communication/radio/5G devices. The wirelessdevices may include, without being limited to, a robot 100 a, vehicles100 b-1 and 100 b-2, an eXtended Reality (XR) device 100 c, a hand-helddevice 100 d, a home appliance 100 e, an Internet of Things (IoT) device100 f, and an Artificial Intelligence (AI) device/server 400. Forexample, the vehicles may include a vehicle having a wirelesscommunication function, an autonomous vehicle, and a vehicle capable ofperforming communication between vehicles. Herein, the vehicles mayinclude an Unmanned Aerial Vehicle (UAV) (e.g., a drone). The XR devicemay include an Augmented Reality (AR)/Virtual Reality (VR)/Mixed Reality(MR) device and may be implemented in the form of a Head-Mounted Device(HMD), a Head-Up Display (HUD) mounted in a vehicle, a television, asmartphone, a computer, a wearable device, a home appliance device, adigital signage, a vehicle, a robot, etc. The hand-held device mayinclude a smartphone, a smartpad, a wearable device (e.g., a smartwatchor a smartglasses), and a computer (e.g., a notebook). The homeappliance may include a TV, a refrigerator, and a washing machine. TheIoT device may include a sensor and a smartmeter. For example, the BSsand the network may be implemented as wireless devices and a specificwireless device 200 a may operate as a BS/network node with respect toother wireless devices.

The wireless devices 100 a to 100 f may be connected to the network 300via the BSs 200. An AI technology may be applied to the wireless devices100 a to 100 f and the wireless devices 100 a to 100 f may be connectedto the AI server 400 via the network 300. The network 300 may beconfigured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g.,NR) network. Although the wireless devices 100 a to 100 f maycommunicate with each other through the BSs 200/network 300, thewireless devices 100 a to 100 f may perform direct communication (e.g.,sidelink communication) with each other without passing through theBSs/network. For example, the vehicles 100 b-1 and 100 b-2 may performdirect communication (e.g. Vehicle-to-Vehicle (V2V)Nehicle-to-everything (V2X) communication). The IoT device (e.g., asensor) may perform direct communication with other IoT devices (e.g.,sensors) or other wireless devices 100 a to 100 f.

Wireless communication/connections 150 a, 150 b, or 150 c may beestablished between the wireless devices 100 a to 100 f/BS 200, or BS200/BS 200. Herein, the wireless communication/connections may beestablished through various RATs (e.g., 5G NR) such as uplink/downlinkcommunication 150 a, sidelink communication 150 b (or, D2Dcommunication), or inter BS communication (e.g. relay, Integrated AccessBackhaul (IAB)). The wireless devices and the BSs/the wireless devicesmay transmit/receive radio signals to/from each other through thewireless communication/connections 150 a and 150 b. For example, thewireless communication/connections 150 a and 150 b may transmit/receivesignals through various physical channels. To this end, at least a partof various configuration information configuring processes, varioussignal processing processes (e.g., channel encoding/decoding,modulation/demodulation, and resource mapping/demapping), and resourceallocating processes, for transmitting/receiving radio signals, may beperformed based on the various proposals of the present disclosure.

FIG. 15 shows wireless devices, in accordance with an embodiment of thepresent disclosure.

Referring to FIG. 15, a first wireless device 100 and a second wirelessdevice 200 may transmit radio signals through a variety of RATs (e.g.,LTE and NR). Herein, {the first wireless device 100 and the secondwireless device 200} may correspond to {the wireless device 100 x andthe BS 200} and/or {the wireless device 100 x and the wireless device100 x} of FIG. 14.

The first wireless device 100 may include one or more processors 102 andone or more memories 104 and additionally further include one or moretransceivers 106 and/or one or more antennas 108. The processor(s) 102may control the memory(s) 104 and/or the transceiver(s) 106 and may beconfigured to implement the descriptions, functions, procedures,proposals, methods, and/or operational flowcharts disclosed in thisdocument. For example, the processor(s) 102 may process informationwithin the memory(s) 104 to generate first information/signals and thentransmit radio signals including the first information/signals throughthe transceiver(s) 106. The processor(s) 102 may receive radio signalsincluding second information/signals through the transceiver 106 andthen store information obtained by processing the secondinformation/signals in the memory(s) 104. The memory(s) 104 may beconnected to the processor(s) 102 and may store a variety of informationrelated to operations of the processor(s) 102. For example, thememory(s) 104 may store software code including commands for performinga part or the entirety of processes controlled by the processor(s) 102or for performing the descriptions, functions, procedures, proposals,methods, and/or operational flowcharts disclosed in this document.Herein, the processor(s) 102 and the memory(s) 104 may be a part of acommunication modem/circuit/chip designed to implement RAT (e.g., LTE orNR). The transceiver(s) 106 may be connected to the processor(s) 102 andtransmit and/or receive radio signals through one or more antennas 108.Each of the transceiver(s) 106 may include a transmitter and/or areceiver. The transceiver(s) 106 may be interchangeably used with RadioFrequency (RF) unit(s). In the present disclosure, the wireless devicemay represent a communication modem/circuit/chip.

The second wireless device 200 may include one or more processors 202and one or more memories 204 and additionally further include one ormore transceivers 206 and/or one or more antennas 208. The processor(s)202 may control the memory(s) 204 and/or the transceiver(s) 206 and maybe configured to implement the descriptions, functions, procedures,proposals, methods, and/or operational flowcharts disclosed in thisdocument. For example, the processor(s) 202 may process informationwithin the memory(s) 204 to generate third information/signals and thentransmit radio signals including the third information/signals throughthe transceiver(s) 206. The processor(s) 202 may receive radio signalsincluding fourth information/signals through the transceiver(s) 106 andthen store information obtained by processing the fourthinformation/signals in the memory(s) 204. The memory(s) 204 may beconnected to the processor(s) 202 and may store a variety of informationrelated to operations of the processor(s) 202. For example, thememory(s) 204 may store software code including commands for performinga part or the entirety of processes controlled by the processor(s) 202or for performing the descriptions, functions, procedures, proposals,methods, and/or operational flowcharts disclosed in this document.Herein, the processor(s) 202 and the memory(s) 204 may be a part of acommunication modem/circuit/chip designed to implement RAT (e.g., LTE orNR). The transceiver(s) 206 may be connected to the processor(s) 202 andtransmit and/or receive radio signals through one or more antennas 208.Each of the transceiver(s) 206 may include a transmitter and/or areceiver. The transceiver(s) 206 may be interchangeably used with RFunit(s). In the present disclosure, the wireless device may represent acommunication modem/circuit/chip.

Hereinafter, hardware elements of the wireless devices 100 and 200 willbe described more specifically. One or more protocol layers may beimplemented by, without being limited to, one or more processors 102 and202. For example, the one or more processors 102 and 202 may implementone or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP,RRC, and SDAP). The one or more processors 102 and 202 may generate oneor more Protocol Data Units (PDUs) and/or one or more Service Data Unit(SDUs) according to the descriptions, functions, procedures, proposals,methods, and/or operational flowcharts disclosed in this document. Theone or more processors 102 and 202 may generate messages, controlinformation, data, or information according to the descriptions,functions, procedures, proposals, methods, and/or operational flowchartsdisclosed in this document. The one or more processors 102 and 202 maygenerate signals (e.g., baseband signals) including PDUs, SDUs,messages, control information, data, or information according to thedescriptions, functions, procedures, proposals, methods, and/oroperational flowcharts disclosed in this document and provide thegenerated signals to the one or more transceivers 106 and 206. The oneor more processors 102 and 202 may receive the signals (e.g., basebandsignals) from the one or more transceivers 106 and 206 and acquire thePDUs, SDUs, messages, control information, data, or informationaccording to the descriptions, functions, procedures, proposals,methods, and/or operational flowcharts disclosed in this document.

The one or more processors 102 and 202 may be referred to ascontrollers, microcontrollers, microprocessors, or microcomputers. Theone or more processors 102 and 202 may be implemented by hardware,firmware, software, or a combination thereof. As an example, one or moreApplication Specific Integrated Circuits (ASICs), one or more DigitalSignal Processors (DSPs), one or more Digital Signal Processing Devices(DSPDs), one or more Programmable Logic Devices (PLDs), or one or moreField Programmable Gate Arrays (FPGAs) may be included in the one ormore processors 102 and 202. The descriptions, functions, procedures,proposals, methods, and/or operational flowcharts disclosed in thisdocument may be implemented using firmware or software and the firmwareor software may be configured to include the modules, procedures, orfunctions. Firmware or software configured to perform the descriptions,functions, procedures, proposals, methods, and/or operational flowchartsdisclosed in this document may be included in the one or more processors102 and 202 or stored in the one or more memories 104 and 204 so as tobe driven by the one or more processors 102 and 202. The descriptions,functions, procedures, proposals, methods, and/or operational flowchartsdisclosed in this document may be implemented using firmware or softwarein the form of code, commands, and/or a set of commands.

The one or more memories 104 and 204 may be connected to the one or moreprocessors 102 and 202 and store various types of data, signals,messages, information, programs, code, instructions, and/or commands.The one or more memories 104 and 204 may be configured by Read-OnlyMemories (ROMs), Random Access Memories (RAMs), Electrically ErasableProgrammable Read-Only Memories (EPROMs), flash memories, hard drives,registers, cash memories, computer-readable storage media, and/orcombinations thereof. The one or more memories 104 and 204 may belocated at the interior and/or exterior of the one or more processors102 and 202. The one or more memories 104 and 204 may be connected tothe one or more processors 102 and 202 through various technologies suchas wired or wireless connection.

The one or more transceivers 106 and 206 may transmit user data, controlinformation, and/or radio signals/channels, mentioned in the methodsand/or operational flowcharts of this document, to one or more otherapparatuses. The one or more transceivers 106 and 206 may receive userdata, control information, and/or radio signals/channels, mentioned inthe descriptions, functions, procedures, proposals, methods, and/oroperational flowcharts disclosed in this document, from one or moreother apparatuses. For example, the one or more transceivers 106 and 206may be connected to the one or more processors 102 and 202 and transmitand receive radio signals. For example, the one or more processors 102and 202 may perform control so that the one or more transceivers 106 and206 may transmit user data, control information, or radio signals to oneor more other apparatuses. In addition, the one or more processors 102and 202 may perform control so that the one or more transceivers 106 and206 may receive user data, control information, or radio signals fromone or more other apparatuses. In addition, the one or more transceivers106 and 206 may be connected to the one or more antennas 108 and 208 andthe one or more transceivers 106 and 206 may be configured to transmitand receive user data, control information, and/or radiosignals/channels, mentioned in the descriptions, functions, procedures,proposals, methods, and/or operational flowcharts disclosed in thisdocument, through the one or more antennas 108 and 208. In thisdocument, the one or more antennas may be a plurality of physicalantennas or a plurality of logical antennas (e.g., antenna ports). Theone or more transceivers 106 and 206 may convert received radiosignals/channels etc. from RF band signals into baseband signals inorder to process received user data, control information, radiosignals/channels, etc. using the one or more processors 102 and 202. Theone or more transceivers 106 and 206 may convert the user data, controlinformation, radio signals/channels, etc. processed using the one ormore processors 102 and 202 from the base band signals into the RF bandsignals. To this end, the one or more transceivers 106 and 206 mayinclude (analog) oscillators and/or filters.

FIG. 16 shows a signal process circuit for a transmission signal, inaccordance with an embodiment of the present disclosure.

Referring to FIG. 16, a signal processing circuit 1000 may includescramblers 1010, modulators 1020, a layer mapper 1030, a precoder 1040,resource mappers 1050, and signal generators 1060. An operation/functionof FIG. 16 may be performed by, without being limited to, the processors102 and 202 and/or the transceivers 106 and 206 of FIG. 15. Hardwareelements of FIG. 16 may be implemented by the processors 102 and 202and/or the transceivers 106 and 206 of FIG. 15. For example, blocks 1010to 1060 may be implemented by the processors 102 and 202 of FIG. 15.Alternatively, the blocks 1010 to 1050 may be implemented by theprocessors 102 and 202 of FIG. 15 and the block 1060 may be implementedby the transceivers 106 and 206 of FIG. 15.

Codewords may be converted into radio signals via the signal processingcircuit 1000 of FIG. 16. Herein, the codewords are encoded bit sequencesof information blocks. The information blocks may include transportblocks (e.g., a UL-SCH transport block, a DL-SCH transport block). Theradio signals may be transmitted through various physical channels(e.g., a PUSCH and a PDSCH).

Specifically, the codewords may be converted into scrambled bitsequences by the scramblers 1010. Scramble sequences used for scramblingmay be generated based on an initialization value, and theinitialization value may include ID information of a wireless device.The scrambled bit sequences may be modulated to modulation symbolsequences by the modulators 1020. A modulation scheme may includepi/2-Binary Phase Shift Keying (pi/2-BPSK), m-Phase Shift Keying(m-PSK), and m-Quadrature Amplitude Modulation (m-QAM). Complexmodulation symbol sequences may be mapped to one or more transportlayers by the layer mapper 1030. Modulation symbols of each transportlayer may be mapped (precoded) to corresponding antenna port(s) by theprecoder 1040. Outputs z of the precoder 1040 may be obtained bymultiplying outputs y of the layer mapper 1030 by an N*M precodingmatrix W. Herein, N is the number of antenna ports and M is the numberof transport layers. The precoder 1040 may perform precoding afterperforming transform precoding (e.g., DFT) for complex modulationsymbols. Alternatively, the precoder 1040 may perform precoding withoutperforming transform precoding.

The resource mappers 1050 may map modulation symbols of each antennaport to time-frequency resources. The time-frequency resources mayinclude a plurality of symbols (e.g., a CP-OFDMA symbols and DFT-s-OFDMAsymbols) in the time domain and a plurality of subcarriers in thefrequency domain. The signal generators 1060 may generate radio signalsfrom the mapped modulation symbols and the generated radio signals maybe transmitted to other devices through each antenna. For this purpose,the signal generators 1060 may include Inverse Fast Fourier Transform(IFFT) modules, Cyclic Prefix (CP) inserters, Digital-to-AnalogConverters (DACs), and frequency up-converters.

Signal processing procedures for a signal received in the wirelessdevice may be configured in a reverse manner of the signal processingprocedures 1010 to 1060 of FIG. 16. For example, the wireless devices(e.g., 100 and 200 of FIG. 15) may receive radio signals from theexterior through the antenna ports/transceivers. The received radiosignals may be converted into baseband signals through signal restorers.To this end, the signal restorers may include frequency downlinkconverters, Analog-to-Digital Converters (ADCs), CP remover, and FastFourier Transform (FFT) modules. Next, the baseband signals may berestored to codewords through a resource demapping procedure, apostcoding procedure, a demodulation processor, and a descramblingprocedure. The codewords may be restored to original information blocksthrough decoding. Therefore, a signal processing circuit (notillustrated) for a reception signal may include signal restorers,resource demappers, a postcoder, demodulators, descramblers, anddecoders.

FIG. 17 shows a wireless device, in accordance with an embodiment of thepresent disclosure. The wireless device may be implemented in variousforms according to a use-case/service (see FIG. 14).

Referring to FIG. 17, wireless devices 100 and 200 may correspond to thewireless devices 100 and 200 of FIG. 15 and may be configured by variouselements, components, units/portions, and/or modules. For example, eachof the wireless devices 100 and 200 may include a communication unit110, a control unit 120, a memory unit 130, and additional components140. The communication unit may include a communication circuit 112 andtransceiver(s) 114. For example, the communication circuit 112 mayinclude the one or more processors 102 and 202 and/or the one or morememories 104 and 204 of FIG. 15. For example, the transceiver(s) 114 mayinclude the one or more transceivers 106 and 206 and/or the one or moreantennas 108 and 208 of FIG. 15. The control unit 120 is electricallyconnected to the communication unit 110, the memory 130, and theadditional components 140 and controls overall operation of the wirelessdevices. For example, the control unit 120 may control anelectric/mechanical operation of the wireless device based onprograms/code/commands/information stored in the memory unit 130. Inaddition, the control unit 120 may transmit the information stored inthe memory unit 130 to the exterior (e.g., other communication devices)via the communication unit 110 through a wireless/wired interface orstore, in the memory unit 130, information received through thewireless/wired interface from the exterior (e.g., other communicationdevices) via the communication unit 110.

The additional components 140 may be variously configured according totypes of wireless devices. For example, the additional components 140may include at least one of a power unit/battery, input/output (I/O)unit, a driving unit, and a computing unit. The wireless device may beimplemented in the form of, without being limited to, the robot (100 aof FIG. 20), the vehicles (100 b-1 and 100 b-2 of FIG. 14), the XRdevice (100 c of FIG. 14), the hand-held device (100 d of FIG. 14), thehome appliance (100 e of FIG. 14), the IoT device (100 f of FIG. 14), adigital broadcast terminal, a hologram device, a public safety device,an MTC device, a medicine device, a fintech device (or a financedevice), a security device, a climate/environment device, the AIserver/device (400 of FIG. 14), the BSs (200 of FIG. 14), a networknode, etc. The wireless device may be used in a mobile or fixed placeaccording to a use-example/service.

In FIG. 17, the entirety of the various elements, components,units/portions, and/or modules in the wireless devices 100 and 200 maybe connected to each other through a wired interface or at least a partthereof may be wirelessly connected through the communication unit 110.For example, in each of the wireless devices 100 and 200, the controlunit 120 and the communication unit 110 may be connected by wire and thecontrol unit 120 and first units (e.g., 130 and 140) may be wirelesslyconnected through the communication unit 110. Each element, component,unit/portion, and/or module within the wireless devices 100 and 200 mayfurther include one or more elements. For example, the control unit 120may be configured by a set of one or more processors. As an example, thecontrol unit 120 may be configured by a set of a communication controlprocessor, an application processor, an Electronic Control Unit (ECU), agraphical processing unit, and a memory control processor. As anotherexample, the memory 130 may be configured by a Random Access Memory(RAM), a Dynamic RAM (DRAM), a Read Only Memory (ROM)), a flash memory,a volatile memory, a non-volatile memory, and/or a combination thereof.

Hereinafter, an example of implementing FIG. 17 will be described indetail with reference to the drawings.

FIG. 18 shows a hand-held device, in accordance with an embodiment ofthe present disclosure. The hand-held device may include a smartphone, asmartpad, a wearable device (e.g., a smartwatch or a smartglasses), or aportable computer (e.g., a notebook). The hand-held device may bereferred to as a Mobile Station (MS), a User Terminal (UT), a MobileSubscriber Station (MSS), a Subscriber Station (SS), an Advanced MobileStation (AMS), or a Wireless Terminal (WT).

Referring to FIG. 18, a hand-held device 100 may include an antenna unit108, a communication unit 110, a control unit 120, a memory unit 130, apower supply unit 140 a, an interface unit 140 b, and an I/O unit 140 c.The antenna unit 108 may be configured as a part of the communicationunit 110. Blocks 110 to 130/140 a to 140 c correspond to the blocks 110to 130/140 of FIG. 17, respectively.

The communication unit 110 may transmit and receive signals (e.g., dataand control signals) to and from other wireless devices or BSs. Thecontrol unit 120 may perform various operations by controllingconstituent elements of the hand-held device 100. The control unit 120may include an Application Processor (AP). The memory unit 130 may storedata/parameters/programs/code/commands needed to drive the hand-helddevice 100. In addition, the memory unit 130 may store input/outputdata/information. The power supply unit 140 a may supply power to thehand-held device 100 and include a wired/wireless charging circuit, abattery, etc. The interface unit 140 b may support connection of thehand-held device 100 to other external devices. The interface unit 140 bmay include various ports (e.g., an audio I/O port and a video I/O port)for connection with external devices. The I/O unit 140 c may input oroutput video information/signals, audio information/signals, data,and/or information input by a user. The I/O unit 140 c may include acamera, a microphone, a user input unit, a display unit 140 d, aspeaker, and/or a haptic module.

As an example, in the case of data communication, the I/O unit 140 c mayacquire information/signals (e.g., touch, text, voice, images, or video)input by a user and the acquired information/signals may be stored inthe memory unit 130. The communication unit 110 may convert theinformation/signals stored in the memory into radio signals and transmitthe converted radio signals to other wireless devices directly or to aBS. The communication unit 110 may receive radio signals from otherwireless devices or the BS and then restore the received radio signalsinto original information/signals. The restored information/signals maybe stored in the memory unit 130 and may be output as various types(e.g., text, voice, images, video, or haptic) through the I/O unit 140c.

FIG. 19 shows a car or an autonomous vehicle, in accordance with anembodiment of the present disclosure. The car or autonomous vehicle maybe implemented by a mobile robot, a car, a train, a manned/unmannedAerial Vehicle (AV), a ship, etc.

Referring to FIG. 19, a car or autonomous vehicle 100 may include anantenna unit 108, a communication unit 110, a control unit 120, adriving unit 140 a, a power supply unit 140 b, a sensor unit 140 c, andan autonomous driving unit 140 d. The antenna unit 108 may be configuredas a part of the communication unit 110. The blocks 110/130/140 a to 140d correspond to the blocks 110/130/140 of FIG. 16, respectively.

The communication unit 110 may transmit and receive signals (e.g., dataand control signals) to and from external devices such as othervehicles, BSs (e.g., gNBs and road side units), and servers. The controlunit 120 may perform various operations by controlling elements of thevehicle or the autonomous vehicle 100. The control unit 120 may includean Electronic Control Unit (ECU). The driving unit 140 a may cause thevehicle or the autonomous vehicle 100 to drive on a road. The drivingunit 140 a may include an engine, a motor, a powertrain, a wheel, abrake, a steering device, etc. The power supply unit 140 b may supplypower to the vehicle or the autonomous vehicle 100 and include awired/wireless charging circuit, a battery, etc. The sensor unit 140 cmay acquire a vehicle state, ambient environment information, userinformation, etc. The sensor unit 140 c may include an InertialMeasurement Unit (IMU) sensor, a collision sensor, a wheel sensor, aspeed sensor, a slope sensor, a weight sensor, a heading sensor, aposition module, a vehicle forward/backward sensor, a battery sensor, afuel sensor, a tire sensor, a steering sensor, a temperature sensor, ahumidity sensor, an ultrasonic sensor, an illumination sensor, a pedalposition sensor, etc. The autonomous driving unit 140 d may implementtechnology for maintaining a lane on which a vehicle is driving,technology for automatically adjusting speed, such as adaptive cruisecontrol, technology for autonomously driving along a determined path,technology for driving by automatically setting a path if a destinationis set, and the like.

For example, the communication unit 110 may receive map data, trafficinformation data, etc. from an external server. The autonomous drivingunit 140 d may generate an autonomous driving path and a driving planfrom the obtained data. The control unit 120 may control the drivingunit 140 a such that the vehicle or the autonomous vehicle 100 may movealong the autonomous driving path according to the driving plan (e.g.,speed/direction control). In the middle of autonomous driving, thecommunication unit 110 may aperiodically/periodically acquire recenttraffic information data from the external server and acquiresurrounding traffic information data from neighboring vehicles. Inaddition, in the middle of autonomous driving, the sensor unit 140 c mayobtain a vehicle state and/or surrounding environment information. Theautonomous driving unit 140 d may update the autonomous driving path andthe driving plan based on the newly obtained data/information. Thecommunication unit 110 may transfer information about a vehicleposition, the autonomous driving path, and/or the driving plan to theexternal server. The external server may predict traffic informationdata using AI technology, etc., based on the information collected fromvehicles or autonomous vehicles and provide the predicted trafficinformation data to the vehicles or the autonomous vehicles.

The scope of the disclosure may be represented by the following claims,and it should be construed that all changes or modifications derivedfrom the meaning and scope of the claims and their equivalents may beincluded in the scope of the disclosure.

Claims in the present description can be combined in a various way. Forinstance, technical features in method claims of the present descriptioncan be combined to be implemented or performed in an apparatus, andtechnical features in apparatus claims can be combined to be implementedor performed in a method. Further, technical features in method claim(s)and apparatus claim(s) can be combined to be implemented or performed inan apparatus. Further, technical features in method claim(s) andapparatus claim(s) can be combined to be implemented or performed in amethod.

1. A method for transmitting a sidelink-synchronization signal block(SL-SSB) by a first apparatus, the method including: determining a firstresource considered capable of transmitting a first SL-SSB; andtransmitting the first SL-SSB to a second apparatus based on the firstresource.
 2. The method of claim 1, further including: receiving asecond SL-SSB from a third apparatus, wherein the transmitting the firstSL-SSB to the second apparatus includes transmitting the first SL-SSB tothe second apparatus based on the received second SL-SSB and the firstresource.
 3. The method of claim 2, wherein the transmitting the firstSL-SSB to the second apparatus based on the received second SL-SSB andthe first resource includes: determining a second resource among thefirst resource based on a slot format of the first SL-SSB; andtransmitting the first SL-SSB to the second apparatus based on thesecond resource, wherein the second resource represents a resource thatoverlaps with an uplink (UL) resource or a sidelink (SL) resource amongthe first resource.
 4. The method of claim 3, wherein the transmittingthe first SL-SSB to the second apparatus based on the second resourceincludes: transmitting the first SL-SSB to the second apparatus througha resource of a pre-configured resource unit that most precedes in timeamong the second resource.
 5. The method of claim 3, wherein thetransmitting the first SL-SSB to the second apparatus based on thesecond resource includes: deriving a sensing resource among the secondresource based on a sensing operation considering a pre-configuredresource unit; and transmitting the first SL-SSB to the second apparatusthrough the sensing resource.
 6. The method of claim 5, wherein areference signal strength indication (RSSI) value is smallest among aplurality of RSSI values determined based on a plurality of resources ofthe pre-configured resource unit included in the second resource.
 7. Themethod of claim 5, wherein a RSSI value determined based on the sensingresource is smaller than a pre-configured threshold, and wherein thesensing resource is the most advanced in time among a plurality ofresources having an RSSI value smaller than the pre-configuredthreshold, and the plurality of resources are based on the previouslyconfigured resource unit.
 8. The method of claim 2, wherein the secondSL-SSB includes first resource indication information related to aphysical sidelink broadcast channel (PSBCH), and wherein the firstresource is determined based on the first resource indicationinformation.
 9. The method of claim 1, wherein the transmitting thefirst SL-SSB to the second apparatus includes: determining a thirdresource based on a slot format of the first SL-SSB among the firstresource; and transmitting the first SL-SSB to the second apparatusbased on the third resource.
 10. The method of claim 9, wherein thefirst resource is determined based on a starting symbol index and anending symbol index in a slot for the first SL-SSB, and wherein thethird resource represents a resource that overlaps with an UL resourceor an SL resource based on the slot format among the first resource. 11.The method of claim 9, wherein the first resource is determined based ona starting symbol index and a first resource length in a slot for thefirst SL-SSB, and wherein the third resource represents a resource thatoverlaps with an UL resource or an SL resource based on the slot formatamong the first resource.
 12. The method of claim 9, wherein thetransmitting the first SL-SSB to the second apparatus includes:transmitting location information of the first SL-SSB to the secondapparatus through a PSBCH.
 13. The method of claim 12, wherein thelocation information of the first SL-SSB is included in SL systeminformation related to the PSBCH or a demodulation reference signal(DMRS) related to the PSBCH.
 14. A first apparatus transmitting asidelink-synchronization signal block (SL-SSB), the first apparatusincluding: at least one memory storing instructions; at least onetransceiver; and at least one processor connecting the at least onememory and the at least one transceiver, wherein the at least oneprocessor is configured to: determine a first resource consideredcapable of transmitting a first SL-SSB, and control the at least onetransceiver to transmit the first SL-SSB to a second apparatus based onthe first resource.
 15. An apparatus controlling a first terminal, theapparatus including: at least one processor; and at least one computermemory operably coupled by the at least one processor and storinginstructions, wherein, by the at least one processor executing theinstructions, the first terminal is configured to: determine a firstresource considered capable of transmitting a first SL-SSB, and transmitthe first SL-SSB to a second apparatus based on the first resource. 16.(canceled)